code: def test_joint_freq(summarizer):
      w1 = ["one", "two", "three", "four"]
      w2 = ["one", "two", "three", "four"]
      freq = summarizer._joint_freq(w1, w2)
  
      assert freq["one"] == 1.0 / 4
      assert freq["two"] == 1.0 / 4
      assert freq["three"] == 1.0 / 4
      assert freq["four"] == 1.0 / 4
  
      w1 = ["one", "two", "three", "four"]
      w2 = ["one", "one", "three", "five"]
      freq = summarizer._joint_freq(w1, w2)
  
      assert freq["one"] == 3.0 / 8
      assert freq["two"] == 1.0 / 8
      assert freq["three"] == 1.0 / 4
      assert freq["four"] == 1.0 / 8
      assert freq["five"] == 1.0 / 8
  
file_path: sumy/tests/test_summarizers/test_kl.py
imports: from __future__ import absolute_import
  from __future__ import division, print_function, unicode_literals
  import pytest
  from sumy.models.dom._sentence import Sentence
  from sumy.nlp.tokenizers import Tokenizer
  from sumy.summarizers.kl import KLSummarizer
  from ..utils import build_document
label_desc: Use image node_id 7 for calling a global function with example usage: test_joint_freq(summarizer) without return types